Magnetic film forming system

ABSTRACT

A magnetic film forming system which can always apply a magnetic field to a substrate in a constant direction. The magnetic film forming system comprises a vacuum container, a substrate pallet for holding a substrate in the vacuum container and being removable with the substrate held, from the vacuum container, and means for supporting the substrate pallet. Magnetic field generation means are fixed to the substrate pallet for applying a magnetic field to the substrate. When the substrate pallet is removed from the vacuum container, the magnetic field generation means are also taken out together with the substrate.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a system for forming a magnetic film in amagnetic field and more particularly to a magnetic film forming systemhaving a plurality of process chambers, and transport mechanisms fortransporting substrates from one process chamber to another.

2. Description of the Related Art

A conventional inline film forming system is described with reference toFIG. 9. The inline film forming system in FIG. 9 comprises a substrateinlet chamber 2, three process chambers 1 a, 1 b, and 1 c, and asubstrate outlet chamber 3 which are linked in order. Sluice valves 8 a,8 b, 8 c, and 8 d are disposed between each of the chambers. Each of theprocess chambers 1 a, 1 b, and 1 c is provided with a device (not shown)for performing one process such as heating a substrate before filmforming, sputtering film forming, ion beam sputtering film forming, orfilm forming by evaporation. A transport line 5 for transporting asubstrate 101 is extended through the substrate inlet chamber 2, processchambers 1 a, 1 b, and 1 c, and substrate outlet chamber 3.

The sequence for forming a film by using the system will be described.First, a substrate 101 on which a film is to be formed is fed into theinlet chamber 2, which is then evacuated by evacuation installation 9 a.The process chambers 1 a, 1 b, and 1 c, and the outlet chamber 3 areevacuated by evacuation installations 9 b, 9 b, 9 d, and 9 erespectively. After the inlet chamber 2 is evacuated, the separationvalve 8 a is opened and the transport line 5 is operated to transportthe substrate 101 to the process chamber 1 a, which has been alreadyevacuated. In the process chamber 1 a, predetermined steps such asheating the substrate before film formation and film formation areperformed by the processing device installed in the chamber. After thepredetermined steps are performed, the separation valve 8 b is openedand the substrate 101 is transported to the following process chamber 1b over the transport line 5. Upon completion of processing the substrate101 in the process chamber 1 b, the substrate 101 is transported to theprocess chamber 1 c for further processing. After predeterminedprocessing in the process chamber 1 c is complete, the substrate 101 istransported to the outlet chamber 3 from which it is removed. A largenumber of substrates 101 can be fed in sequence into the substrate inletchamber 2 and through the process chambers 1 a, 1 b, and 1 c one afteranother for processing.

In order, to form a film whose magnetic orientation is aligned, a filmforming method in a magnetic field is used by which a film is formedwhile magnetic orientation of film particles is being aligned byapplying a magnetic field. An example of the film forming system in therelated art is given in “Journal of Vacuum Science & Technology A(Composition distribution and magnetic characteristics of sputteredPermalloy films with substrate angle)” second series volume 7, number 3,May/June 1989. This article describes a technique in which a permanentmagnet is attached to a substrate holder which is fixed to a filmforming system and a substrate is mounted on the substrate holder.

To form a magnetic film in a magnetic field by a conventional inlinefilm forming system, magnetic field generation means is fixed outside orinside a process chamber and a magnetic field is applied to a spacewithin the process chamber where a substrate is placed.

An example of a conventional inline system in which magnetic fieldgeneration means is attached outside a sputter film forming processchamber will be described with reference to FIG. 7. As shown here,Helmholtz magnetic coils 4 a, 4 b, 4 c, and 4 d are disposed outside aprocess chamber 1 d which is provided with a magnetic target 3 and an RFpower supply 2 for applying voltage to the magnetic target 3. TheHelmholtz magnetic coils 4 a, 4 b, 4 c, and 4 d form a magnetic field 6in a space where a substrate 101 is placed. The substrate 101 issupported by a transport line (not shown). Magnetic sputter particlessputtered from the magnetic target 3 are affected by the magnetic field6 to form a film magnetically oriented on the substrate 101.

An example of a conventional inline system in which magnetic fieldgeneration means is attached inside a sputter film forming processchamber will be described with reference to FIG. 8. As shown here,permanent magnets 4 e and 4 f are disposed at places around a substrate101 carried in a process chamber 1 e. The permanent magnets 4 e and 4 fare supported by magnetic support means 7 fixed to the process chamber 1e. Since the permanent magnets 4 e and 4 f form a magnetic field 6 in aspace where the substrate 101 is supported by a transport line (notshown), sputter particles sputtered from the magnetic target 3 areaffected by the magnetic field 6 to form a film magnetically oriented onthe substrate 101.

However, a conventional film forming system having such magnetic fieldgeneration means suffers from the problem that when a substrate is takenout from the film forming system after a film has been formed, it isplaced out of the magnetic field of the magnetic field generation means.Thus, if the substrate is taken out from the film forming system in thestate in which it is not completely cooled after the film has beenformed, the magnetic orientation of the film is not aligned, there bydegrading the magnetic characteristic. To prevent this inconvenience,the substrate must be left in the film forming system until it iscompletely cooled after film formation. It takes time until thesubstrate is completely cooled, substantially lowering the throughput ofthe system.

Forming a magnetic multilayer film by using the conventional inlinesystem having such magnetic field generation means, suffers from thefollowing problems:

(1) To form a multilayer film, a number of film forming process chamberswhich differ in film forming source must each be provided with magneticfield generation means. At the time, it is very difficult to completelymatch the various directions of magnetic fields applied to substrates bythe magnetic field generation means in the process chambers. This causesthe orientation of the magnetic film to vary from one layer to another,degrading the magnetic characteristic of the magnetic film. There aretwo main reasons why the directions of the magnetic fields in theprocess chambers cannot be matched are as follows. First, to completelymatch the directions of the magnetic fields generated by the magneticfield generation means in the film forming process chambers, thedirections of coils and magnets must be matched completely. However, itis technically very difficult to completely match the directions ofcoils and magnets which are separated from each other and adjustment ofthe directions requires that the system be stopped over a long period oftime. Second, when a substrate is transported, the substrate turns andits direction will vary.

(2) When the magnetic field generation means is installed outside eachfilm forming process chamber, a magnetic field must be generated withinthe process chamber, thus a large magnetic field generation means needsto be installed, there by increasing costs.

(3) Process chambers must be located apart from each other to preventmagnetic fields generated by magnetic field generation means in thecontiguous process chambers from affecting each other to become unevenmagnetic fields. Thus, the line in the system is longer as compared witha normal inline system having no magnetic field generation means,leading to inconvenient installation of the former system.

(4) When a substrate is transported to the contiguous film formingprocess chamber after film formation, it is temporarily placed out ofthe magnetic field. Thus, if it is transported to the next processchamber in the state in which the substrate is not completely cooledafter film formation, it is cooled out of the magnetic field, and sothus the magnetic orientation of the film is not aligned, this degradingthe magnetic characteristic of the magnetic material. To prevent thisinconvenience, the substrate must be left in the process chamber untilit is completely cooled after film formation. It takes time to cool thesubstrate, which substantially lowers the throughput of the line.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the invention to provide a film formingsystem which can form a magnetic film having a high magneticcharacteristic by always applying a magnetic field in a constantdirection to a substrate in the system.

To this end, according to a first embodiment of the invention, there isprovided a magnetic film forming system comprising a vacuum container, asubstrate pallet for holding a substrate in the vacuum container andbeing removable, with the substrate held, from the vacuum container,means for supporting the substrate pallet in the vacuum container, meansfor forming a film on the substrate, and magnetic field generation meansfor applying a magnetic field to the substrate. The magnetic fieldgeneration means is fixed to the substrate pallet. When the substratepallet is removed from the vacuum container, the magnetic fieldgeneration means is taken out from the vacuum container together withthe substrate pallet.

According to a second embodiment of the invention, there is provided amagnetic film forming system comprising a vacuum container, a substratepallet for holding a substrate, transport means for supporting thesubstrate pallet in the vacuum container and transporting the substratepallet, means for forming a film on the substrate, and magnetic fieldgeneration means for applying a magnetic field to the substrate. Themagnetic field generation means is fixed to the substrate pallet. Whenthe substrate pallet is transported by the transport means, the magneticfield generation means is transported together with the substrate palletin the vacuum container.

In the magnetic film forming system according to the first embodiment ofthe invention, a substrate on which a film is formed is retained on thesubstrate pallet and the substrate together with the substrate palletcan be transported in the vacuum container and taken out therefrom. Whena film is formed, the substrate together with the substrate pallet issupported by the support means in the vacuum container. The film formingmeans forms a film on the substrate on the substrate pallet supported bythe support means. The magnetic film generation means applies a magneticfield to the substrate and orients the magnetization direction of a filmwhen it is formed.

In the invention, the magnetic field generation means, which is fixed tothe substrate pallet, always applies a magnetic field to the substratein a constant direction unless the substrate slips off the substratepallet. Therefore, a magnetic field is always applied to the substratein a constant direction not only when a film is formed, but also whilethe substrate pallet is moved in the vacuum container or taken outtherefrom. So long as the substrate is held on the substrate pallet, amagnetic field is applied regardless of where the substrate is placed inthe vacuum container or whether it is placed inside or outside thevacuum container. Thus, even if the substrate is moved before a film iscooled, film orientation does not vary. Further, since the magneticfield generation means is mounted on the same substrate pallet as thesubstrate, a magnetic field can be applied at close range. Smallmagnetic field generation means having a small magnetic field strengthcan apply a magnetic field efficiently, implementing a small system.Since the magnetic field generation means is taken out from the systemtogether with the substrate pallet, the magnetic field direction canalso be adjusted easily.

The magnetic film forming system according to the second embodiment ofthe invention is provided with means for transporting the substratepallet in the vacuum container. The vacuum container can also be dividedinto a number of process chambers. In such an inline film formingsystem, while a substrate is transported from one chamber to another, amagnetic field is always applied to the substrate in a constantdirection by the magnetic field generation means on the substratepallet, thus there is no risk of the magnetic field applicationdirection varying slightly between each process chamber. Further, sincethe magnetic field generation means is mounted on the same substratepallet as the substrate, a magnetic field can be efficiently applied atclose range by small magnetic generation means, implementing a smallinline film forming system. Since the magnetic field generation means istaken out from the system together with the substrate pallet, themagnetic field direction can also be adjusted easily even if the inlinemagnetic film forming system comprises a plurality of process chambers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a process chamber of an inline filmforming system according to one embodiment of the invention;

FIG. 2(A) is a perspective view of a substrate pallet in the inline filmforming system in FIG. 1;

FIG. 2(B) is a sectional view taken on line b—b of FIG. 2(A);

FIG. 3 is a block diagram showing the overall arrangement of the inlinefilm forming system in FIG. 1;

FIGS. 4(A) and 4(B) are partial sectional views showing theconfiguration of conveyance means of the inline film forming system inFIG. 1;

FIG. 5 is a block diagram showing another arrangement of the inline filmforming system according to the embodiment of the invention;

FIG. 6 is a block diagram showing a further arrangement of the inlinefilm forming system according to the embodiment of the invention;

FIG. 7 is a sectional view showing the configuration of a conventionalfilm forming system for forming a film in a magnetic field;

FIG. 8 is a sectional view showing the configuration of a conventionalfilm forming system for forming a film in a magnetic field;

FIG. 9 is a block diagram showing the overall configuration of aconventional inline film forming system;

FIG. 10 is an illustration showing magnetic lines of force of a magneticfield when permanent magnets which have a short bar form are used withthe substrate pallet in FIG. 2(A);

FIG. 11 is an illustration showing magnetic lines of force of a magneticfield when permanent magnets which have a long bar form are used withthe substrate pallet in FIG. 2(A);

FIG. 12 is a perspective view showing another example of substratepallet that can be used with the inline film forming system according tothe embodiment shown in FIG. 3;

FIG. 13 is an illustration showing magnetic lines of force of a magneticfield applied to the substrate mounted on the substrate pallet in FIG.12;

FIG. 14 is a top view showing another example of substrate pallet thatcan be used with the inline film forming system according to theembodiment shown in FIG. 3;

FIG. 15(A) is a top view showing the forms of permanent magnets mountedon a substrate pallet that can be used with the inline film formingsystem according to the embodiment shown in FIG. 3;

FIG. 15(B) is a top view showing the forms of permanent magnets mountedon a substrate pallet that can be used with the inline film formingsystem according to the embodiment shown in FIG. 3;

FIG. 16 is an illustration showing magnetic lines of force of magneticfield when too small auxiliary magnets are used on 10 the substratepallet shown in FIG. 14;

FIG. 17 is an illustration showing magnetic lines of force of magneticfield when too large auxiliary magnets are used on the substrate palletshown in FIG. 14;

FIG. 18 is an illustration showing magnetic lines of force of magneticfield when auxiliary magnets of proper size are used on the substratepallet shown in FIG. 14; and

FIG. 19 is a sectional view showing the arrangement of a film formingsystem according to another embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the accompanying drawings, there are shown inline filmforming systems according to embodiments of the invention.

The configuration of an inline film forming system according to oneembodiment of the invention will be described with reference to FIG. 3.The inline film forming system according to this embodiment of theinvention comprises three film forming process chambers 11 a, 11 b, and11 c, and a transport chamber 14. A substrate inlet chamber 12 and asubstrate outlet chamber 13 are disposed on both ends of the transportchamber 14.

The transport chamber 14 contains y direction transport mechanisms 11 a,11 b, and 11 c for getting a substrate pallet 21 in and out of the filmforming process chambers 11 a, 11 b, and 11 c respectively, and xdirection transport mechanisms 15 a, 15 b, and 15 c for moving thesubstrate 21 in the x direction. The inlet chamber 12 is provided with adoor 17 a for taking in a substrate pallet 21 from the exterior of thetransport chamber 14 and an inlet chamber transport mechanism 15 d forpassing the taken-in substrate pallet 21 to the x direction transportmechanism 15 a in the transport chamber 14. The outlet chamber 13 isprovided with an outlet chamber transport mechanism 15 e for receivingthe substrate pallet 21 having been processed from the x directiontransport mechanism 15 c in the transport chamber 14 and a door 17 bthrough which the substrate pallet 21 is taken to the exterior of thetransport chamber 14.

Separation valves 18 a, 18 b, and 18 c are disposed between the processchambers 11 a, 11 b, and 11 c and the transport chamber 14 respectivelyfor separating the chambers in such a manner that they can be opened andclosed. A separation valve 18 d is located between the inlet chamber 12and the transport chamber 14 and a separation valve 18 e is locatedbetween the outlet chamber 13 and the transport chamber 14. Evacuationinstallations 19 a, 19 b, and 19 c are connected to the process chambers11 a, 11 b, and 11 c respectively. An evacuation installation 19 d isconnected to the transport chamber 14. Evacuation installations 19 e and19 f are connected to the inlet chamber 12 and the outlet chamber 13respectively.

Next, the structure of the substrate pallet 21 will be described withreference to FIGS. 2(A) and 2(B). As shown in FIG. 2(B), the substratepallet 21 is a plate-like pallet where a through hole 21 a is formed atthe center. The side of the through hole 21 a is stepped to hold asubstrate 24. An orientation flat is formed on the sides of thesubstrate 24 and the through hole 21 a to prevent the substrate 24 fromturning, as shown in FIG. 2(A). On the substrate pallet 21, twopermanent bar magnets 28 a and 28 b are disposed parallel and facingeach other, with the through hole 21 a between them. The permanentmagnets 28 a and 28 b apply a magnetic field to the substrate 24 in thedirection parallel to the orientation flat 10.

Next, the internal structure of the process chamber 11 a, 11 b, 11 cwill now be described with reference to FIG. 1. The process chamber 11 awill be provided with a pallet support mechanism 25 a for supporting thesubstrate pallet 21, a target 23 a for sputter film forming on thesubstrate 24, and an RF power supply 22 a for applying a voltage to thetarget 23 a. Although only the process chamber 11 a is shown in FIG. 1,each of the process chambers 11 b and 11 c has the same arrangement asthe process chamber 11 a. The process chamber 11 b (not shown) isprovided with a pallet support mechanism 25 b, a target, and an RF powersupply in the same arrangement as the process chamber 11 a. The processchamber lc (not shown) is provided with a pallet support mechanism 25 c,a target, and an RF power supply in the same arrangement as the processchamber 11 a. Each of the pallet support mechanisms 25 a, 25 b, and 25 cis provided with a drive mechanism (not shown) for driving the substratepallet 21 in the z direction.

Next, the configuration and operation of the x direction transportmechanisms 15 a, 15 b, and 15 c and the y direction transport mechanisms16 a, 16 b, and 16 c will be described with reference to FIGS. 4A and4B. The x direction transport mechanism 15 a and y direction transportmechanism 16 a are not shown in FIG. 4, but the former has a similarstructure to those of other x direction transport mechanisms and thelatter has a similar structure to those of other y direction transportmechanisms. The x direction transport mechanism 15 b has caterpillars 31b, as shown in FIG. 4(A). A motor 33 b is connected via a gear 32 b toone axle of the caterpillars 31 b for driving the caterpillars 31 b. Themotor 33 b drives the caterpillars 31 b as commanded by a controller 41.

A pair of sensors 34 b and 35 b are disposed inside the caterpillars 31b. The sensors 34 b and 35 b are adapted to emit light to an object anddetect reflected light from the object for detecting the presence of theobject. They are spaced at a distance equal to the width of thesubstrate pallet 21. Output signals of the sensors 34 b and 35 b areinput to the controller 41, which determines where the substrate pallet21 is positioned on the x direction transport mechanism 15 b from theoutput signals of the sensors 34 b and 35 b for driving the motor 33 b,and then stops the substrate pallet 21 at the front of the y directiontransport mechanism 16 b. Likewise, the x direction transport mechanism15 c also comprises caterpillars 31 c, a gear 32 c, a motor 33 c, andsensors 34 c and 35 c.

To move the substrate pallet 21 on the caterpillars 31 b onto thecaterpillars 31 c, the controller 41 rotates the motors 33 b and 33 c inthe forward direction. To move the substrate pallet 21 on thecaterpillars 31 c onto the caterpillars 31 b, the controller 41 rotatesthe motors 33 b and 33 c in the reverse direction. The motors 33 b and33 c can be rotated in different directions independently of the motorof the x direction transport mechanism 15 a (not shown). Therefore,while the x direction transport mechanism 15 a is driven in the forwarddirection to take in a substrate pallet 21 from the inlet chamber 12,the x direction transport mechanisms 15 b and 15 c can be driven in thereverse direction, for example, to move another substrate pallet 21 fromthe x direction transport mechanism 15 c onto the x direction transportmechanism 15 b.

The y direction transport mechanism 16 b comprises lift mechanisms 36 bdisposed inside the caterpillars 31 b, a fork member 38 b for moving asubstrate pallet placed thereon, and a driving motor 39 b for drivingthe fork member 38 b in the y direction via a gear. The y directiontransport mechanism 16 c comprises lift mechanisms 36 c, a fork member38 c, and a driving motor 39 c. Drive mechanisms 71 b and 71 c areconnected to the lift mechanisms 36 b and 36 c for driving them in the zdirection.

Here, the operation of transporting a substrate pallet 21 from thetransport chamber 14 to the process chamber 11 b will be described. Thelift mechanisms 36 b lift up the pallet 21 placed on the caterpillars 31b in the z direction (up and down) to float it from the caterpillars.The fork member 38 b is inserted between the substrate pallet 21 liftedup by the lift mechanisms 36 b and the caterpillars 38 b. When the liftmechanisms 36 b are made to descend in this state, the substrate pallet21 is placed on the fork member 38 b.

Next, the driving motor 39 b is driven to move the fork member 38 b onwhich the substrate pallet 21 is placed to the process chamber 11 b. Thepallet support mechanism 25 b in the process chamber 11 b is made torise when the substrate pallet 21 is carried in the process chamber 11b. The pallet support mechanism 25 b supports the substrate pallet 21and receives it from the fork member 38 b. Again, the driving motor 39 bis driven to return the fork member 38 b to the transport chamber 14.The pallet support mechanism 25 b is moved up and down to thepredetermined height appropriate for forming a film and is made tosupport the substrate pallet 21 at the position until the film formingis complete. After the film forming is complete, by reversing theoperation sequence, the substrate pallet 21 is moved from the processchamber 11 b onto the caterpillars 31 b in the transport chamber 14. Allof the driving gears 39 b and 39 c, the drive mechanisms 71 b and 71 cof the lift mechanisms 36 b and 36 c in the transport chamber 14, anddrive mechanisms (not shown) of the pallet support mechanisms 25 b and25 c in the process chambers 11 b and 11 c are driven at the timingsdescribed above as commanded by the controller 41.

The separation valves 18 a, 18 b, and 18 c are opened only when thesubstrate pallet 21 is moved between the transport chamber 14 and theprocess chambers 11 a, 11 b, and 11 c. The separation valve 18 d isopened only when the substrate pallet 21 is transported from the inletchamber 12 to the transport chamber 14. The separation valve 18 e isopened only when the substrate pallet 21 is transported from thetransport chamber 14 to the outlet chamber 13. The separation valves 18a, 18 b, 18 c, 18 d, and 18 e are opened and closed under the control ofthe controller 41.

Next, the operation of the inline film forming system according to anthe embodiment will be described by taking the producing of a multilayerfilm comprising three magnetic materials A, B, and C laminated in orderof A, B, C, and B on a substrate as an example. First, a target 23 amade of material A is located in the process chamber 11 a, a target madeof material B is located in the process chamber 11 b, and a target madeof material C is located in the process chamber 11 c. The operation ofthe sections of the inline film forming system according to theembodiment is controlled by the controller 41.

The user first places a substrate 24 on the substrate pallet 21 at theexterior of the system. Since the permanent magnets 28 a and 28 b aremounted on the substrate pallet 21 as described above, a magnetic fieldis applied to the substrate placed on the pallet 21. Next, the useropens the door 17 a of the inlet chamber 12, places the substrate pallet21 on which the substrate 24 is placed on the transport mechanism 15 din the inlet chamber, and then closes the door. The controller 41evacuates the inlet chamber 12 by the evacuation installation 19 e. Italso evacuates the transport chamber 14 and the process chambers 11 a,11 b, and 11 c by the evacuation installations 19 d, 19 a, 19 b, and 19c respectively. After evacuation, the separation valve 18 d is openedand the transport mechanism 15 d in the inlet chamber and the xdirection transport mechanism 15 a are driven in the forward directionto carry the substrate pallet 21 to the front of the film formingprocess chamber 11 a (the front of the y direction transport mechanism16 a). Next, the substrate pallet 21 is carried by the y directiontransport mechanism 16 a into the film forming process chamber 11 aalready evacuated, is placed on the substrate pallet support mechanism25 a, and then the separation valve 18 a is closed.

Once the substrate pallet 21 is carried into the process chamber 11 a, avoltage is applied from the RF power supply 22 a to the target 23 a forstarting sputtering. Sputter particles of material A collide against theface of the substrate 24 on the side of the target 23 a where a film ofmaterial A is formed. At the time, magnetic field 6 is applied to thesubstrate 24 by the permanent magnets 28 a and 28 b fixed on thesubstrate pallet 21 for aligning the magnetic directions of the sputterparticles to form a magnetically oriented film.

After the film forming is complete, the separation valve 18 a is openedand the y direction transport mechanism 16 a is driven to move thesubstrate pallet 21 into the transport chamber 14 and pass it to the xdirection transport mechanism 15 a. Next, the x direction transportmechanisms 15 a and 15 b are driven at the same time in the forwarddirection to carry the substrate pallet 21 to the front of the filmforming process chamber 11 b (the front of the y direction transportmechanism 16 b).

Meanwhile, magnetic field 6 is applied to the substrate 24 from thepermanent magnets 28 a and 28 b, thus even if the substrate pallet istaken out from the process chamber 11 a before the film of material A iscompletely cooled, film orientation is not disordered. The operation isrepeated to form a film of material B on the film of material A in theprocess chamber 11 b.

Successively, the operation is repeated to further form a film ofmaterial C on the film of material B in the process chamber 11 c.

Upon completion of the film forming in the process chamber 11 c, the xdirection transport mechanisms 15 c and 15 b are driven at the same timein the reverse direction again to transport the substrate pallet 21 tothe front of the process chamber 11 b. Again, a film forming step isperformed in the process chamber 11 b to form a film of material B onthe film of material C. After the step has been executed, the xdirection transport mechanisms 15 b and 15 c are driven in the forwarddirection to transport the substrate pallet 21. When the substratepallet 21 arrives in front of the separation valve 18 e, the separationvalve 18 e is opened and the x direction transport mechanism 15 c andthe outlet chamber transport mechanism 15 e are driven at the same timein the forward direction to move the substrate pallet 21 to the outletchamber 13, and then the separation valve 18 e is closed. At this time,the outlet chamber 13 must have been evacuated. After the outlet chamber13 is restored to atmospheric pressure, the user opens the door 17 b inthe outlet chamber 13 and removes the substrate pallet 21 on which thesubstrate 24 is placed to the exterior of the outlet chamber 13.

Since the permanent magnets 28 a and 28 b are mounted on the substratepallet 21 used in the embodiment, the magnetic field 6 is always appliedto the substrate 24 in the constant direction. Therefore, even while thesubstrate pallet is transported in the transport chamber 14, themagnetic field 6 is always applied to the substrate 24. If a film isformed by sputtering, the substrate 24 is heated. Formerly, a substratewas placed out of the magnetic field during transportation before it wascompletely cooled, thus the substrate was sometimes cooled outside themagnetic field, causing orientation of the magnetic film to vary. In theinline film forming system according to this embodiment, a magneticfield is also applied during the transportation, thus there is no riskthat the orientation of the formed magnetic film will by disordered.

Since the inline film forming system in this embodiment applies amagnetic field to the substrate 24 by the permanent magnets 28 a and 28b of the substrate pallet 21 at all times, the direction of magneticfield applied to the substrate 24 is always constant. This eliminatesthe need for a cumbersome step of finely adjusting the directions of themagnetic fields of the magnetic field generation means disposed in theprocess chambers for a complete match, and also eliminates theinconvenience of degrading the magnetic characteristic of the magneticfilm caused by a change in the magnetic field direction during thecourse of film forming. Further, since the permanent magnets 28 a and 28b are mounted on the same substrate pallet 21 as the substrate 24, amagnetic field can be applied at close range. Small magnetic fieldgeneration means having small magnetic field strength, such as permanentmagnets, would be able to apply a magnetic field efficiently,implementing a small inline film forming system. Since the magneticfield generation means is taken out from the system together with thesubstrate pallet, the magnetic field direction can also be adjustedeasily.

Further, in the inline film forming system according to the embodiment,no transport mechanisms are disposed in the process chambers 11 a, 1 b,11 c, which are separated from the transport chamber 14 by theseparation valves 18 a, 18 b, and 18 c respectively, but transportmechanism are located in the transport chamber 14. Therefore, sputterparticles in the process chambers do not adhere to the x directiontransport mechanisms 15 a, 15 b, 15 c, or the y direction transportmechanisms 16 a, 16 b, 16 c, and there is no risk of inconvenience suchthat adherence of sputter particles to the drive parts of the transfermechanisms make it difficult to move the drive parts. This eliminatesthe need for periodic maintenance to prevent adherence and enablescontinuous running over a long period of time.

In the inline film forming system according to this embodiment, the xdirection transport system is divided into x direction transportmechanisms 15 a, 15 b, and 15 c which correspond to the process chambers11 a, 11 b, and 11 c respectively and can be driven independently ofeach other to transport the substrate pallet 21 in different directions.Thus, when a number of substrate pallets 21 are being carried in thesystem at a time, some substrate pallets 21 can be transported in theforward direction while a different substrate pallet 21 is transportedin the reverse direction by another transport mechanism. Therefore, tolaminate two films of the same material B put with another film between,for example, for forming a multilayer film, some substrate pallets 21can be driven in the forward direction for forming a film of a differentmaterial A while a different substrate pallet 21 is returned in thereverse direction for again forming a film of material B. Therefore, amultilayer film can be formed efficiently by using a small number ofprocess chambers.

Further, since x direction transport mechanisms 15 a, 15 b, and 15 c areindependent of each other corresponding to the process chambers, whenthe film forming system is delivered to the user, the transport systemcan be divided for transportation. Formerly, the transport system wasunable to be divided for transportation and the maximum line length waslimited by the length of transportation facilities. Since the transportsystem in this embodiment can be divided for transportation, an inlinefilm forming system having a sufficiently long line required for theuser can be provided without being limited by the length oftransportation facilities.

Although permanent magnets are used as the magnetic field generationmeans in the embodiment, magnetic coils can also be used in place of thepermanent magnets. Further, the inline film forming system can alsoincorporate drive means for changing the direction of a permanent magneton the substrate pallet to the direction as commanded. The drive meanswould enable production of a multilayer film by applying a magneticfield to each layer in any desired different direction. Although everyprocess chamber is provided with film forming means in the embodiment,process chambers for heating, etching, milling, etc., can also beinstalled as a matter of course.

The process chambers 11 a, 11 b, and 11 c can also be installed on bothsides of the transport chamber 14, as shown in FIG. 5, therebyremarkably shortening the overall length of the transport line.

FIG. 6 shows an example of the inline film forming system furtherincluding three process chambers 11 g, 11 h, and 11 i as spare chambers.The process chamber 11 g includes a target of the same material A as theprocess chamber 11 a; the process chamber 11 h includes a target of thesame material B as the process chamber 11 b; and the process chamber 11i includes a target of the same material C as the process chamber 11 c.The transport chamber 14 is provided with x direction transportmechanisms 15 g, 15 h, and 15 i and y direction transport mechanisms 16g, 16 h, and 16 i for the process chambers 11 g, 11 h, and 11 i. At thebeginning, a multilayer film is formed in the process chambers 11 a, 11b, and 11 c. If the target in the process chamber 11 a is exhausted, theprocess in the process chamber 11 a is switched to the process chamber11 g to continue forming the multilayer film in the process chambers 11g, 11 b, and 11 c. While it is being formed in the process chambers 11g, 11 b, and 11 c, the target in the process chamber 11 a is replacedwith a new one. Next, when it becomes necessary to clean the processchamber 11 b, the process in the process chamber 11 b is switched to theprocess chamber 11 h to continue forming the multilayer film in theprocess chambers 11 g, 11 h, and 11 c. Meanwhile, the target in theprocess chamber 11 b is replaced with a new one. Thus, the sparechambers with which the process chambers are provided enable continuousrunning of the system even if inconvenience occurs or maintenance isrequired in the process chamber.

Since the process chambers 11 a, 11 b, and 11 c are separated from thetransport chamber 14 by the separation valves 18 a, 18 b, and 18 crespectively, foreign materials such as sputter particles do not adherein the transport chamber 14. Therefore, necessity for maintenance andinspection in the transport chamber 14 is remarkably reduced and furtherthe system can be continuously run over a long period of time.

Next, the form of the permanent magnets on the substrate pallet 21 inthe embodiment will be discussed in more detail.

On the substrate pallet 21 shown in FIG. 2, two permanent bar magnets 28a and 28 b are disposed parallel and facing each other, with thesubstrate 24 between them so that a uniform magnetic field 6 is appliedto the substrate 24. At this time, whether or not magnetic lines offorce of magnetic field 6 in the portion of the substrate 24 arecompletely parallel is determined by the length of the permanent magnet28 a, 28 b

FIG. 10 shows magnetic lines of force when permanent bar magnets 108 aand 108 b each having the length comparable to the diameter of thesubstrate 24 are used, for example, as the permanent magnets 28 a and 28b. Since the magnetic lines of force at both ends of the magnet 108 a,108 b have a nature of bending outwardly, the center of the substrate 24and the portions near both ends of the magnet 108 a, 108 b differ indirection of magnetic lines of force, as shown in FIG. 10, and magneticfield distribution of small skew angle is not obtained. The skew anglerefers to the horizontal angle difference between the desired and actualmagnetic field directions. Since the peripheral portion and center ofthe substrate 24 differ in direction of an applied magnetic field, thefilm formed on the substrate 24 varies in direction of magnetization.

FIG. 11 shows magnetic lines of force when permanent bar magnets 118 aand 118 b each having a length which is about twice the diameter of thesubstrate 24 are used. In the example, the substrate 24 is placed apartfrom both ends of the permanent bar magnets 118 a, 118 b. Thus, even ifthe magnetic lines of force on both ends of the permanent magnets 118 a,118 b bend outwardly, completely parallel magnetic lines of force fromthe center of the permanent magnet 118 a, 118 b are distributed acrossthe substrate 24 and a magnetic field having magnetic lines of forcealigned in direction can be applied to the substrate 24.

Therefore, the length of the permanent magnets 28 a, 28 b of thesubstrate pallet 21 in FIG. 2 may be determined according to theorientation characteristic of magnetization direction of a filmrequired. For example, if the orientation of a film formed on asubstrate 24 must be completely uniform on the substrate 24, longpermanent magnets 118 a and 118 b as shown in FIG. 11 are used to applycompletely parallel magnetic lines of force to the substrate 24. Forexample, if the orientation of a film formed on a substrate 24 mayslightly vary, short permanent magnets 108 a and 108 b as shown in FIG.10 can be used as the permanent magnets 28 a and 28 b. If the shortpermanent magnets 108 a and 108 b can be used, the size of the substratepallet 21 can be made small, providing the advantage of enabling thesize of the inline film forming system according to the embodiment to bemade small.

If permanent magnets formed as described below are used, short permanentmagnets would be able to apply completely parallel magnetic lines offorce to a substrate 24, thus the substrate pallet 21 and the inlinefilm forming system can be made small in size, as described in moredetail below with reference to FIG. 12.

As shown in FIG. 12, two permanent bar magnets 128 a and 128 b aredisposed in parallel on a pallet 21. Auxiliary magnets 124 a and 124 bmade of the same material as the permanent magnets 128 a and 128 b arefixed to the sides at both ends of the permanent magnets 128 a and 128 bfacing a substrate 24. The forms of the substrate 24 and substratepallet 21 are the same as shown in FIG. 2, and will therefore not bediscussed again.

Next, FIG. 13 shows directions of magnetic lines of force applied to thesubstrate 24 by the permanent magnets 128 a, 128 b and the auxiliarymagnets 124 a, 124 b shown in FIG. 12. The auxiliary magnets 124 a and124 b enhance the strength of the magnetic field applied to thesubstrate 24 from both ends of the permanent magnet 128 a, 128 b. Forthis reason, outward swelling of magnetic lines of force of magneticfield 6 at both ends of the permanent magnet 128 a, 128 b lessens, andeven magnets 128 a, 128 b each having the length comparable to thediameter of the substrate 24 can apply a magnetic field to the entiresubstrate 24 in a uniform direction. Thus, if auxiliary magnets 124 aand 124 b are installed, the permanent magnet 128 a, 128 b, which has athe length comparable to the diameter of the substrate 24, can apply amagnetic field aligned in direction to the whole substrate 24 when amagnetic film is formed. As a result, the size of the substrate pallet21 can be made small.

FIGS. 15(A) and 15(B) show the forms of other permanent magnets. In FIG.15(A), auxiliary magnets 164 a and 164 b are disposed on sides at bothends of permanent magnets 128 a and 128 b facing a substrate 24 andfurther auxiliary magnets 174 a and 174 b are disposed on sides ofauxiliary magnets 164 a and 164 b facing the substrate 24. In FIG.15(B), the faces of permanent magnets 148 a and 148 b facing thesubstrate 24 are each processed like a circular arc without auxiliarymagnets, thereby making both ends of the permanent magnets 148 a and 148b thicker than the centers thereof. In FIGS. 15(A) and 15(B), themagnetic flux density at both ends of each of the permanent magnets 128a and 128 b and 148 a and 148 b increases gradually towards both theends, thus disorder of magnetic lines of force applied to the substrate24 can be lessened.

FIG. 14 shows another example of a substrate pallet on which permanentmagnets provided with auxiliary magnets are mounted. On the substratepallet 139 shown in FIG. 14, two auxiliary substrates 107 are placedeach on either side of a substrate 24. The substrate 24 and theauxiliary substrates 107 are retained by a through hole whose edges arestepped, disposed on the substrate pallet 139. The auxiliary substrates107 are located to monitor the nature of a film formed on the substrate24 by using films formed on the auxiliary substrates 107. Therefore, amagnetic field must also be applied to the auxiliary substrates 107under the same conditions as the substrate 24.

To attempt to apply a magnetic field whose magnetic lines of force areparallel to the auxiliary substrates 107 and the substrate 24 by usingonly permanent bar magnets 138 a and 138 b on the substrate pallet wherethe auxiliary substrates 107 are placed each on either side of thesubstrate 24, permanent magnets 138 a and 138 b in the form of very longbars must be used to position both the ends thereof sufficiently outsidethe auxiliary substrates 107. In the example in FIG. 14, both the endsof the permanent bar magnets 138 a and 138 b are positioned just outsidethe auxiliary substrates 107, but auxiliary magnets 134 a and 134 bcause the strength of magnetic field at both ends of the permanentmagnets 138 a and 138 b to be enhanced, lessening outward swelling ofmagnetic lines of force at both ends. Thus, a uniform magnetic field canalso be applied to the entire auxiliary substrates 107 in the samedirection as the substrate 24.

At the substrate pallets shown in FIGS. 12, 14, and 15(A), thedirections and density of magnetic lines of force of magnetic fieldapplied to the substrate 24, etc., are determined by the balance of thesize of magnetization of the permanent magnets 128 a, 128 b, 138 a, 138b and that of the auxiliary magnets 124 a, 124 b, 134 a, 134 b, 164 a,164 b, 174 a, 174 b (that is, magnetic flux density of the magneticfield generated). The size and forms of auxiliary magnets required toprovide a uniform magnetic field are determined as discussed below.

As an example, the sequence of finding the size of auxiliary magnets 134a and 134 b on the substrate pallet 139 in FIG. 14 will be describedwith reference to FIGS. 16 to 18. First, auxiliary magnets 144 a, 144 b,154 a, 154 b, 134 a, and 134 b of proper size were located at both endsof permanent magnets 138 a and 138 b and magnetic lines of force ofmagnetic field generated were calculated by a large-scale computer witha magnetic field analysis simulation program. Magnetic field analysissimulation was executed under calculation conditions of two dimensions,axis symmetry with remaining magnetization size, forms, and arrangementof the permanent magnets 138 a and 138 b and auxiliary magnets 144 a,etc., as parameters. A generally known program was used for the magneticfield analysis simulation program. The auxiliary magnets 144 a, 144 b,154 a, 154 b, 134 a, and 134 b were made of the same material as thepermanent magnets 138 a and 138 b.

The calculation results are shown in FIGS. 16 to 18. As shown in FIG.16, when the auxiliary magnets 144 a and 144 b were used, they were sosmall that the generated magnetic field was weak and it was not possibleto suppress the swelling of the magnetic lines of force at both ends ofthe permanent magnets 138 a and 138 b. Thus, the magnetic lines of forceof the magnetic field applied to auxiliary substrates 107 becameoutwardly swelled curves, and it was not possible to match the directionof the magnetic lines of force of the magnetic field applied to theauxiliary substrates 107 with that of the magnetic field applied to thesubstrate 24.

On the other hand, as shown in FIG. 17, when the auxiliary magnets 154 aand 154 b were used, they were so large that the generated magneticfield was too strong and the magnetic lines of force of the magneticfield of the auxiliary magnets 154 a, 154 b became swollen curves towardthe substrate 24 in a region 100 between the substrate 24 and theauxiliary substrate 107, and it was not possible to make the directionof the magnetic lines of force of the magnetic field applied to theauxiliary substrates 107 match that of the magnetic field applied to thesubstrate 24. It was also found that the magnetic flux density of themagnetic field applied to the auxiliary substrates 107 differs from thatof the magnetic field applied to the substrate 24.

As shown in FIG. 18, when the auxiliary magnets 134 a and 134 b wereused, they were proper in size, thus magnetic lines of force of themagnetic field applied to the substrate 24 and auxiliary substrates 107were parallel and spaced at given intervals and equal to each other inmagnetic flux density and direction. Therefore, the auxiliary magnets134 a and 134 b were mounted on the substrate pallet 139, as shown inFIG. 14.

Thus, to produce auxiliary magnets, a magnetic field is previouslysimulated as described above to determine the size and arrangement ofauxiliary magnets so that magnetic lines of force become parallel on thesubstrate 24 and auxiliary substrates 107 and are spaced at givenintervals. Then, permanent magnets are processed.

As shown in FIG. 15(B), to determine the forms of permanent magnets 148a and 148 b, a magnetic field is also first simulated as described aboveto find the forms of the permanent magnets 148 a and 148 b for providinga uniform magnetic field.

Thus, in the inline film forming system according to this embodiment, asmall substrate pallet with short permanent magnets can be used bymaking the magnetic flux density of a magnetic field generated at bothends of the permanent magnet on the substrate pallet larger than that atthe center thereof. In addition, since only small auxiliary magnets needto be mounted, a small amount of magnetic material is required to makelight and economical magnets. Such a small and light substrate pallet iseasily transported and is appropriate for use with an inline filmforming system. Also, process and transport chambers of an inline filmforming system can be small-sized. Further, if small permanent magnetsare used, the system is unlikely to be affected by a magnetic field of asputter target in a magnetron sputter process chamber.

Although the auxiliary magnets are made of the same material as thepermanent magnets in this embodiment, they can also be made of differentmaterials as a matter of course. If auxiliary magnets are made of amaterial with larger magnetization than permanent magnets, a uniformmagnetic field can be provided by smaller auxiliary magnets.

Further, permanent magnets are used as means for applying a magneticfield to the substrate 24 in this embodiment, but coils can also beused, in which case magnetic lines of force can be spaced at constantintervals and match in direction as in the embodiment by increasing thenumber of windings of coils disposed at both ends of a substrate andenhancing an electric current. In this case, simulation of magneticlines of force is also executed to determine the strength of magneticfield at both ends.

Although the inline film forming system is discussed in this embodiment,the invention is not limited to this embodiment. For example, a supportmechanism 130 for supporting a substrate pallet can also be fixed forplacing a substrate pallet 21 in a vacuum container 125 of only onechamber as shown in FIG. 19. The vacuum container 125 is provided with apower supply 102 and a sputter target 123 as film forming means.Permanent magnets 28 a and 28 b are installed on the substrate pallet21. Auxiliary magnets can also be installed on the substrate pallet. Insuch a vacuum system, if the substrate pallet 21, etc., is used, asubstrate 24 together with the substrate pallet 21 can be taken out.Therefore, even if it is taken out from the vacuum container 125 beforea film on the substrate 24 is completely cooled, film orientation is notdisordered because applying a magnetic field from the permanent magnets28 a, 28 b continues. Since the substrate pallet can be taken outimmediatly after a film is formed, the throughput of the vacuumcontainer 125 can be raised.

Regardless of where a substrate is placed in the system, the magneticfilm forming system can always apply a magnetic field to the substratein a constant direction so long as the substrate is mounted on thesubstrate pallet, thus the system can manufacture magnetic films havingexcellent magnetic characteristics.

What is claimed is:
 1. A magnetic film forming system comprising: avacuum container; a substrate pallet for holding a substrate in saidvacuum container, said substrate pallet being removable from said vacuumcontainer while still holding said substrate; means for supporting saidsubstrate pallet in said vacuum container; means for forming a film onsaid substrate; and magnetic field generation means for applying amagnetic field to said substrate; said magnetic field generation meansbeing fixed to said substrate pallet such that it is removed from saidvacuum container along with said substrate pallet, when said substratepallet is removed from said vacuum container; and said substrate beingprovided with a means which prevents the rotation of said substrate onsaid substrate pallet in order to maintain a predetermined direction ofsaid substrate relative to the magnetic field applied by said magneticfield generation means.
 2. A magnetic film forming system comprising: avacuum container; a substrate pallet for holding a substrate; transportmeans for supporting said substrate pallet in said vacuum container andtransporting said substrate pallet; means for forming a film on saidsubstrate; and magnetic field generation means for applying a magneticfield to said substrate; said magnetic field generation means beingfixed to said substrate pallet such that it is transported along withsaid substrate pallet, when said substrate pallet is transported by saidtransport means; and said substrate being provided with a means whichprevents the rotation of said substrate on said substrate pallet inorder to maintain a predetermined direction of said substrate relativeto the magnetic field applied by said magnetic field generation means.3. A magnetic film forming system as claimed in claim 2 wherein saidmagnetic field generation means is a permanent magnet.
 4. A magneticfilm forming system as claimed in claim 2 wherein said magnetic fieldgeneration means is a pair of permanent magnets disposed facing eachother with a space for holding said substrate therebetween and amagnetic flux density of a magnetic field formed at both ends of saidpermanent magnet is larger than that of a magnetic field formed at acenter of said permanent magnet.
 5. A magnetic film forming system asclaimed in claim 2, wherein said vacuum container has a process chamberfor forming a film on said substrate and a transport chamber linked tosaid process chamber and said transport means is disposed in saidtransport chamber and has means for carrying in a substrate pallet fromsaid process chamber into said transport chamber and means for carryingout said substrate pallet from said transport chamber into said processchamber.
 6. A magnetic film forming system as claimed in claim 5 whereina plurality of said process chambers are contained, said means forcarrying in and said means for carrying out being disposed correspondingto each of said plurality of process chambers, and said transport meansfurther includes means for moving said substrate pallet from the saidmeans for carrying in and said means for carrying out corresponding toone process chamber to those corresponding to another.
 7. A magneticfilm forming system as claimed in claim 6 wherein said means for movingis separated into a plurality of portions corresponding to saidplurality of process chambers on a one-to-one basis and said pluralityof portions can be driven independently of each other in both forwardand reverse directions.
 8. An inline film forming system comprising: atransport chamber comprising transport means; a plurality of processchambers being disposed along length of said transport chamber andlinked thereto; film forming means disposed in said plurality of processchambers; a substrate pallet for holding a substrate and beingtransported by said transport means while holding said substrate;magnetic field generation means being fixed to said substrate pallet andfor applying a magnetic field to said substrate; said magnetic fieldgeneration means being transported by said transport means together withsaid substrate pallet; and said substrate being provided with a meanswhich prevents the rotation of said substrate on said substrate palletin order to maintain a predetermined direction of said substraterelative to the magnetic field applied by said magnetic field generationmeans.
 9. An inline film forming system as claimed in claim 8 whereinsaid transport means has means for carrying in said substrate palletfrom said transport chamber into said process chamber, means forcarrying out said substrate pallet from said process chamber into saidtransport chamber, and means for moving said substrate pallet along alength of said transport chamber; said means for carrying in and saidmeans for carrying out being disposed for each of said plurality ofprocess chambers; said means for moving being separated into a pluralityof portions corresponding to said plurality of process chambers on aone-to-one basis; and said plurality of portions being able to be drivenindependently of each other in both forward and reverse directions. 10.A magnetic film forming system comprising: a vacuum container; asubstrate holder for holding a substrate in said vacuum container; meansfor forming a film on said substrate; and a pair of magnetic fieldgeneration means for applying a magnetic field to said substrate; saidpair of magnetic field generation means being fixed on the substrateholder and facing each other with a space for holding said substratetherebetween; and wherein a magnetic flux density of a magnetic fieldformed at both ends of said magnetic field generation means is largerthan that of a magnetic field formed at a center of said magnetic fieldgeneration means.
 11. A magnetic film forming system as claimed in claim10 wherein said magnetic field generation means is a permanent magnet.12. A magnetic film forming system comprising: a vacuum container; asubstrate pallet transported through the vacuum container; a substrateheld on the substrate pallet; magnetic field generation means mounted onthe substrate pallet for applying a magnetic field to the substrate; andwherein the magnetic field generation means remains mounted on thesubstrate pallet when the substrate pallet is withdrawn from the vacuumcontainer so as to maintain alignment of the magnetic field applied tothe substrate.
 13. A magnetic film forming system according to claim 12further comprising transport means for transporting said substratepallet into and out of said vacuum container.
 14. A magnetic filmforming system according to claim 13 further comprising means forforming a film on the substrate.
 15. A magnetic film forming systemaccording to claim 14 further comprising means for preventing rotationof the substrate on the substrate pallet.